


Only Human

by WheelsUpIn_Five



Series: How To Be Human [1]
Category: Supernatural
Genre: Angst, Dean Winchester Saves Castiel from the Empty, Fluff, Human Castiel (Supernatural), Human!Castiel - Freeform, Jack and Sam are also there briefly, M/M, the secret good spn that lives in my head
Language: English
Status: Completed
Published: 2021-02-27
Updated: 2021-03-11
Packaged: 2021-03-18 00:47:56
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,441
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29725770
Author URL: https://archiveofourown.org/users/WheelsUpIn_Five/pseuds/WheelsUpIn_Five
Summary: Dean saves Castiel from the empty, and in turn starts to learn what it's like to be human.
Relationships: Castiel/Dean Winchester
Series: How To Be Human [1]
Series URL: https://archiveofourown.org/series/2184666
Comments: 4
Kudos: 82





	1. Rescue

**Author's Note:**

> This is slightly AU in that Cas has never been human before and Jack isn't God (and Dean got out of that barn in 15x20)
> 
> Enjoy!

The Empty is both everything and nothing like Castiel had expected it to be. It chews him hollow. Leaving him to decay from the inside out, his heart no longer beating but lungs burning for air as they fight against the bitter sludge that fills them; that fills everything. It’s cold.

So cold. 

Time doesn’t touch the Empty. Not in the way that matters. Seconds, minutes, hours, days, months, maybe  _ years _ , he isn't sure, they all blend into one, incomprehensibly folding back onto each other. This is what his eternity looks like. Counting the splintered seconds dragging by. The screams of his memories echoing off the infinite stretch of the walls, suffocating him with pain, but offering him the only company he has. 

Sometimes Dean still calls his name. It’s those moments that hurt the most.

_ Dean. _

He still aches for him. Seeing him behind his eyelids, broken but beautiful, his soul always bright. He’ll never regret giving his life for him. He’d do it all again in a heartbeat. He only hopes that once everything has blown over, Dean can finally be happy. 

He only hopes that Dean Winchester has been _ saved. _

* * *

Dean rolls his shoulders, the scar tissue pulling between his shoulder blades. It still hurts sometimes, but he’s learned to ignore it. 

A lot has gone through his mind in the last six months: grief, loss, pain, despair, but through it all, he always thinks of Cas. He attended physiotherapy for Cas, he eats better for Cas, he gets out of bed for Cas. 

He prays for Cas. Every morning and every night without fail.

It’s only now he sees a glimmer of hope at the end of this fucked up tunnel. It is only now, as he watches Sam prepare the spell that would get him into the Empty, does he allow himself to think of having Cas back in his arms.

Dean’s skin itches in anticipation. He's been dreaming of this day since the moment he lost him, and he’s barely slept since his sleeping pills ran out. He still doesn’t know what it’s like there. It could be anything. 

He doesn’t have the time to dwell on it, they have one shot at this and a very limited window to do it. Even with Jack boosting the energy of the spell, Sam can only hold the gateway open for so long, and Dean isn’t coming back alone. 

Dean paces another circle around the library, clutching his angel blade in one hand, his knuckles white, and the glass bottle tied around his neck in the other. Cas’ last words still echo in his head. They never stopped. Trapped by the hope and depression that coat his mind. 

_ I love you. Goodbye Dean. _

It’s almost time. 

Sam runs through a final check of everything he's set out, Jack by his side, as Dean carefully steps into the centre of the circle of symbols and herbs in the middle of the hard wood floor, all the furniture pushed back to the edges of the room.

Dean turns over his palm, his eyes tracing the lines of the symbol that stains it. It’ll help him find Cas, but no one can tell him  _ how _ it will, but he has faith in Sam. It will work. He gently swipes his thumb over the markings. 

“You ready?” Sam asks from behind him. Dean clenches his fist, the angel blade cool in his hand, bottle heavy around his neck. 

“Always have been.”

Sam gives him one final nod before he starts chanting in a language Dean doesn’t recognise, eyes fixed on the place the gateway would open. Wind starts to whip around him, burning his eyes, the roar in his ears drowning out Sam’s voice. The air crackles with power. 

Everything stills.

A void tears open the space in front of him. 

It’s now or never.

Dean doesn’t look back. 

The silence is deadly inside. Darkness stretching infinitely out around him, he himself contrasting against it in perfect visibility. He pulls his jacket closer to his body, his fingers already stiff with cold. Pushing the wetness seeping into the bottoms of his pants out of his mind, he blindly steps forwards, one foot after the other.

“Cas!” he calls, his voice ringing out into the nothing. He opens his palm and screams erupt in the distance. “Cas!” He tries again, breaking into a jog, following the sound. It gets louder and louder as he gets deeper and deeper until it’s almost too much to bear, his voice raw from calling, body shaking and fingers numb. 

Then he sees it.

A small piece of the oh-so familiar trench-coat showing beneath the black sludge.  _ Cas _ . He falls to his knees, shovelling handfuls of sludge off him until his head is above the surface, cradled in Dean's lap.

“Hey, Cas, you with me?” No response. “This might hurt a little.” Dean fumbles to hold him in place with frozen fingers as he gently drags the angel blade across Cas’ throat above his adams apple, the silver blue of his grace flowing into the bottle he holds to the wound. 

Cas coughs and chokes, barely conscious, black sludge spilling from his mouth. Dean clutches his coat to keep him from slipping.

“Well well well, what do we have here?” A nasally voice with a strange accent asks. Dean looks up to see Cas standing over them — but not  _ his _ Cas. “Trying to play the knight in shining armour are we? Well it’s not going to work. He’s all mine.”

Dean clutches him tighter. Hell no, he hasn’t come this far to end up empty handed. 

“You think I give a fuck? He’s graceless, you can’t fucking have him.” He gathers Cas in his arms and stands on shaky legs, Cas’ grace securely around his neck, warm against freezing skin. The other Cas — the Empty — grabs his shoulder, tight enough to bruise, their touch icy. 

“You’re too loud Dean,” they tsk, “I think I’ll make an exception and add a human to my collection. I can think of a few ways to shut you up.” Black sludge bleeds from their hand, crawling up Dean’s arm. His heart hammers in his throat.

Dean  _ screams _ . The loudest he ever has.

The Empty drops, covering their ears with their hands, letting out a cry of their own.

Dean doesn’t linger to watch, taking off in the opposite direction as fast as he can, Cas’ head limp against his shoulder. His legs and lungs burn, pain shooting through his back and shoulders. By the time the gateway comes into view, his whole body is threatening to collapse, every staggered step painful. 

“I’ve got you.” His throat hurt, something metallic sticking to the back of his tongue. “We’re going home.”

He stumbles through the gateway, his knees connecting with the floor in time for the gateway to snap shut behind him. The light burns his eyes. He holds Cas tightly to his chest. 

Sam leans heavily against the table, blood running from his nose and down his chin as Jack slumps against the wall, rubbing his temples. No one speaks.

Cas stirs in his arms, still covered in the black sludge and Dean fails to blink back tears. 

“He’s back?” Jack asks quietly, tired hope clear on his face. 

“Yeah,” Dean sniffs, a couple of hot tears falling onto Cas' coat. “Yeah he is.” He pulls Cas’ grace from around his neck and sets it carefully on the floor. It barely half fills the small bottle. “Can you seal this properly? I’m gonna go get us cleaned up.” 

Sam nods, straightening his back. “Do you need a hand?”

Dean shakes his head before dragging himself back to his feet and making his way to the bathroom, Cas still in his arms.

He’s thankful to have not gotten much of the sludge on his skin, most of it sticking to clothes besides the dark smear on his neck and jaw from Cas’ hair. Cas on the other hand is covered in it, a layer of the sickening sludge residing between each layer of clothing and his skin. He refills the tub several times before the water remains somewhat clear, mumbling soft reassurance with every swipe of the cloth over Cas’ skin.

* * *

It’s different. 

Drifting in an idyllic sense of comfort, with a familiar rumble somewhere in the distance. The sound draws closer. He tries to pull away, but it’s like he’s full of lead. He isn’t supposed to be comfortable.

Something is wrong.

“Hey, Cas, it’s okay.” The familiar voice speaks around him. “You’re safe, I’ve got you.” _ Dean _ . He reaches for him, his eyes struggling to focus in the soft lighting.

“Hey, hey, it’s okay. You’re in the bunker. I’ve got you.” A warm hand wraps around his wrist, placing it back in the water surrounding him. Cas can’t help but to grab Dean’s arm and hold him there, grounding himself. Dean doesn’t pull away. 

Slowly things become sharper. His body, left only in his underwear, submerged by warm water, tinged grey. He struggles to process his surroundings. His stomach hurts.

“Dean.” The words are warm on his lips.

“Hey, Cas,” his voice wavers. “Welcome home, buddy.” His face slowly comes into focus, his eyes bloodshot, but his smile softening them. Light catches on the drying tear tracks on his cheeks. Castiel reaches out, his head too foggy to stop himself from cupping Dean’s face, smudging the tracks with his thumb. He never wants to stop touching him. Dean pulls back, grabbing a glass from the vanity and filling it with water.

“Here.” Dean gently presses the cool glass into his hand.

Castiel takes a tentative sip. Sure, he's drunk before, but he's never gotten to experience what it is to  _ taste _ something. His stomach rolls and he swallows hard, looking at Dean with panicked eyes. He slaps a hand over his mouth as his stomach twists again, shoving himself upright, and the glass back into Dean’s hands. 

Dean seems to get the message this time, grabbing the trash can just in time for black sludge to claw its way up Castiel’s throat. It’s so cold, it burns. He barely gets the time to breathe before he retches again, his eyes watering. Dean’s hand rests warm and steady between his shoulder blades, rubbing soothing circles into his skin. 

“What’s happening to me?” Castiel gasps, coughing at the rawness of his throat.

“I’m- I’m sorry, Cas.” Dean lowers his eyes. “I had to remove your grace to get you out. I don’t think your body agrees with being filled with that stuff.” He swallows. “We still have your grace. I can get it for you now. If you want.” Dean doesn’t wait for an answer before pulling away.

“Don’t-” Castiel grabs Dean’s arm. He can’t be alone. Not now. “Let me try being human first.” Maybe now he will be able to live like him,  _ for _ him, but he had nothing to offer without his powers. “If that’s okay.” He adds, looking down, his hand falling from Dean’s shoulder. 

“Of course,” Dean says softly, offering the glass to him again. Castiel takes it and rinses out his mouth. The thought of taking another sip makes his stomach turn, but Dean keeps looking at him expectantly, so he presses the glass to his lips, and lets the water travel, cold, to his stomach. Dean smiles.

Dean decides Castiel is warm enough after a few more minutes of comfortable silence, and helps him out of the bath. Wrapping a robe around his shoulders, he holds him steady. Castiel’s head pounds, his thoughts broken and out of order, his limbs and eyelids heavy. It’s hard not to lean into the warmth of Dean’s hands, and relax against his arms when his body wants nothing else. 

Dean lingers at his bedside, then the doorway, words unspoken, heavy between them, but neither of them open their mouths. The tension doesn’t fade when he leaves.

Castiel knows not to confuse love with guilt. 

So when he is left alone in the cold expanse of his bed, he clutches Dean’s robe close to his chest, thinking of the warmth of his skin. Cheap cologne and gunpowder; it still smells like him. 


	2. Chapter 2

**Notes for the Chapter:**

> This chapter turned out a little more angsty than planned so i apologise for that  
> And also the fact this update is almost a week late, but school has been kicking my ass and i struggled a lot with this chapter just in general.

Castiel shakes. Curling tightly into himself, the remnants of his dream still clutching his mind. The Empty still claws at him, surrounding him, everywhere,  _ everything, _ choking him. It’s not real. He was prepared to stay there for eternity, he can handle a night of it. 

His lungs burn, his head spins, he can’t see. It’s too dark. It’s  _ not _ real.

Throwing the blankets off himself, he follows the weak light peeking beneath the door, stumbling through into the hallway. The air bites at his skin. The hall too cramped but too big, the oxygen levels too low for his human body. His breath’s ripped from his chest, as he staggers into the library, the robe still clutched to his chest. His eyes immediately lock with Dean’s.

“Woah, Cas, hey buddy,” Dean says, putting down the drink he’s nursing, rushing to his feet and crossing the floor. Castiel doesn't think twice, meeting him halfway and pulling him into a hug, burying his face into the crook of his neck. Dean’s arms wrap securely around him, holding him close enough for the heat of his body to radiate through his clothes.

“It's too dark.” Castiel’s words are muffled by Dean’s shirt, shame colouring his cheeks. It sounds childish out loud. He doesn’t elaborate, but Dean doesn’t seem to expect him too, his touch easy and  _ safe _ . 

He clutched Dean like a lifeline until Dean eased them apart, his hands resting on his Cas’ shoulders. Even hugs feel different as a human. Tighter, warmer, or maybe that’s just  _ Dean _ . 

“Okay, first we’ll put this on.” Dean gently takes the robe from Castiel’s hands and wraps it around his shoulders. Castiel hadn’t realised he was cold. Or maybe the bite had slipped his mind while he was lost in Dean’s arms. “And I’ll find you something to sleep in.” Dean’s touch lingers at Castiel’s sleeve before he walks through to the hallway, flicking on the light, and pausing for him to follow. 

Castiel could list a thousand words to describe Dean’s room before he came close to ‘unfamiliar’, but things are different now. He’s human. Dean knows he loves him. The space is sacred, but now Castiel has nothing more to offer.

It’s not that he’s bitter about not having his feelings returned, but that he has given all that he has to offer, and it was rejected. At some point Dean’s pity will run dry and Castiel will be left with nothing. He’s seen enough movies, read enough books, to know when your feelings aren’t returned, the friendship won’t last. 

Castiel stands at the foot of the bed as Dean digs through his draws and produces a tightly rolled shirt and red flannel pants. The shirt has  _ AC/DC _ written across the front of it, and is soft with wear, but a little tight across his shoulders when he pulls it on. Dean’s worn it a number of times before, often after sleepless nights he never wants to talk about. The pants are new though, yet to be worn in. 

Castiel runs the bottom of the shirt between his fingers. He shouldn’t let himself read into it, but he can't help but see the implications of lending someone a personal object of comfort. He shakes his head, pressure building behind his eyes. It’s not Love. Do not confuse love for guilt.

It’s too much. Emotions burning beneath the surface, churning in his chest. It doesn't make sense. It’s all white overwhelming noise, pushing at the walls of his mind, searching for weakness. He’s drowning and seeing Dean only pushes him deeper. 

“Thank you,” he chokes out, balling the bottom of the shirt in his fist. “I- I have to go.” His voice breaks on the last word. Dean opens his mouth but Castiel is out the door before he can hear what he has to say. 

The light in his room stays on. It’s too bright to sleep, but it’s better than the alternative. He doubts he would be able to sleep anyway, not with the amount of concentration required to keep this mess of emotions under control; the good and the bad bleeding together into something incomprehensible. He felt as an angel, but this is so much worse. It’s closing in around him and he doesn’t know how to get out. He’d never been claustrophobic, but the walls of his room are starting to feel too close for comfort.

He mourns the loss of the robe, abandoned on the end of Dean’s bed, his hands cold and empty. The shirt smells of Dean’s washing powder, but not of _ him _ . 

It is the small comforts Castiel tries to hold onto. The weight of the blankets wrapped around his shoulders, the safe and familiar trench coat now hanging on the back of his door. He tries not to look at how bare the walls are, how empty the lone desk sits. In time it may become home to him, but for now it's just the room he hangs his clothes in. They say home is where the heart is.

He doesn’t think about Dean’s bedroom.

A soft knock on the door jars him from his thoughts. Castiel freezes, willing them to leave. If he feigns sleep he doubts they would bother him, but there’s a quiet nudge at the door and he  _ knows _ it’s him. Dean. The stillness stretches between them. 

“Hey Cas, so I know you probably don’t want to talk about it, and I get it,” Dean laughs bitterly. “Trust me I get it. But I’m here- we’re here for you if you need anything. Me, Sam, Jack… He’s just a kid, but I know he’s itching to hug you.” There’s quiet shuffling outside his door and for a minute he thinks Dean will open it, but he doesn’t. Castiel can’t tell if he’s grateful or disappointed.

The silence is heavy, what feels like miles between them wound tight, nothing but a mere few feet and a piece of wood separating them. “What I’m trying to say is-” a shaky intake of breath, his words barely audible “-I’m asking you to stay, man. My door’s always open for you, just don’t… leave. Not again,  _ please _ .

“Anyway,” Dean clears his throat, “I have a lamp for you. I’ll just leave it out here. You don’t have to take it if you don’t want to.” A pause, “I’ll see you in the morning okay? Goodnight, Cas.” Two more soft knocks follow his words, then his footsteps descend back down the hall. 

Castiel breathes. In, and out.

Still clutching the blankets around his shoulders, he gets up, the wood floors cold on bare feet. Slowly, he opens the door and peaks out through the gap, not to make a sound, before pushing it open further to bring the lamp in. He sets it down gently on his bedside table. There’s a small note taped to the lamp shade that reads ‘ _ If you need  _ _ anything _ _ , you know where to find me _ ’ in Dean’s hasty scrawl. ‘Anything’ is underlined three times. 

Castiel holds it like it could disintegrate from the lightest of touches, gently placing it in the empty draw of his bedside table. Love swells in his chest, sadness, soon to follow. Torn between pushing him away so it hurts less when he has to leave, and clinging to every bit of attention he gives him, making the most of it while he has it. But he asked him to stay, and if that will let him see him smile one more time, he will.

Stay.

The weight of his words sit heavily in his chest as he turns off his light in favour for the lamp. It’s softer, the low glow gentle on his eyes, warming the room like Dean’s, creating false familiarity. He sits on the edge of the bed, wrapping his arms around himself and slowly lowers himself to the mattress, still cocooned in the blankets. His chest is still hollow and cold, like part of him has been left in the empty. It’s not the type of chill that can be fixed through external means. It’s the kind that seeps into his organs, threatening to freeze them.

He forces a small smile as tears well in his eyes.

He’ll be okay.

One foot in front of the other. He’ll leave when he has too, but until then, he’ll savour every moment.

**Notes for the Chapter:**

> I hope you liked it!
> 
> I promise future installations of this series will tend to be more fluffy :)
> 
> Kudos and comments are always appreciated! Tell me what you liked and what you like and any constructive criticism you might have! I wanna hear it all!
> 
> You can find me on tumblr @wheelsupin-five

**Author's Note:**

> Thanks for reading, I hope you liked it :)
> 
> Kudos and comments are always appreciated!   
> Feel free to let me know what else you'd like to see in the series too. I'm hoping to have the next chapter up in about a week 
> 
> Tumblr: wheelsupin-five (come say hi?)


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